Bug 33832

Summary:	mt352_read_register throws readreg error on bt878 dvb-t card (Nebula DigiTV)
Product:	v4l-dvb	Reporter:	Juho Rutila (juho.rutila+kernelbugs)
Component:	dvb-core	Assignee:	dvb-core (v4l-dvb_dvb-core)
Status:	RESOLVED OBSOLETE
Severity:	high	CC:	alan
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.38.3	Subsystem:
Regression:	No	Bisected commit-id:

Description Juho Rutila 2011-04-22 14:39:39 UTC

mt352 driver crashes in certain situations.

Here is the setup
01:00.0 VGA compatible controller: ATI Technologies Inc RV505 CE [Radeon X1550 64-bit]
04:00.0 Multimedia video controller: Brooktree Corporation Bt878 Video Capture (rev 11)
04:00.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture (rev 11)

DVB-T card uses dvb_bt8xx driver. The error messages are
Apr 22 16:37:50 laika kernel: [  687.777413] mt352_read_register: readreg error (reg=0, ret==-6)
Apr 22 16:37:50 laika kernel: [  687.778010] mt352_read_register: readreg error (reg=20, ret==-6)
Apr 22 16:37:50 laika kernel: [  687.778607] mt352_read_register: readreg error (reg=21, ret==-6)
Apr 22 16:37:50 laika kernel: [  687.779204] mt352_read_register: readreg error (reg=9, ret==-6)
Apr 22 16:37:50 laika kernel: [  687.779801] mt352_read_register: readreg error (reg=13, ret==-6)
Apr 22 16:37:50 laika kernel: [  687.780406] mt352_read_register: readreg error (reg=14, ret==-6)
Apr 22 16:37:50 laika kernel: [  687.781003] mt352_read_register: readreg error (reg=15, ret==-6)
Apr 22 16:37:50 laika kernel: [  687.781600] mt352_read_register: readreg error (reg=16, ret==-6)
Apr 22 16:37:50 laika kernel: [  687.782197] mt352_read_register: readreg error (reg=17, ret==-6)

Driver works fine for some time. Then when I turn my monitor (attached with dvi to the ATI video card) on, mt352 driver crashes and starts to produce those errors.

This problem sounds like a hardware problem, but I am filing this bug if there is something that can be done in the software side. I have tried to switch PCI and PCIe slots to no avail.